Retaining walls, containment systems, levies and similar structures are commonly used in a variety of applications, such as erosion control, flood protection, coastal protection, slope stabilization for slopes and embankments of highways and railways, or in areas where the landscape needs to be shaped severely. Generally, these structures are subject to substantial lateral pressures from the soil, backfill, water, etc. maintained behind the structures. These pressures are predominantly horizontal and tend push the structure forward (and potentially over) if not properly addressed.
Structures are commonly built with sandbags and/or soil bags. Where sandbags or soil bags are utilized, lateral pressures apply forces against back surfaces of the bags such that each row of bags may have a tendency to slide forward over the bags of a row below. Essentially, bags on top are pushed forward over bags on bottom. Accordingly, structures should be designed to provide shear strength to resist sliding and prevent failures.
Methods to provide additional stability and resistance against lateral pressures of structures made from sandbags and/or soil bags may include interconnecting members to connect the bags. Typically, interconnecting members will be plate-like structures having a plurality of protrusions from both a top surface and a bottom surface of the plate-like structures. The interconnecting members will usually be placed across adjacent bags of a first row of the structure with a bag of the next row covering the interconnecting member. The top protrusions will protrude into the top bag and the protrusions on the bottom will protrude into portions of the adjacent bags below the interconnecting member. The process may be continued until the desired height of the structure is obtained. This process will essentially interconnect the bags and provides stability. The structures may further incorporate sheets of geogrid to further stabilize the structure and the geogrid may be anchored to individual units of the structure via interconnecting members.
Generally, the plurality of protrusions of the interconnecting members may be spikes, cones or similar protrusions. The protrusions are generally the same on either side of the plate-like structures, and for most interconnecting members, the top surface and the bottom surface are interchangeable. Because typical protrusions are merely spikes, cones, or similar, the protrusions have angular sides or edges in multiple directions with respect to their interaction with the bags. Because the lateral forces are generally essentially horizontal, the forces push against the protrusion at an angle rather than against a flat surface thereby reducing stability and resistance against the applied forces. The angular sides and/or edges lead to decreased shear resistance and susceptibility to sliding of the bags.
Accordingly, there is need for improved interconnecting units that provide increased shear strength/sliding resistance and enhanced stability to the protrusions thereof.